The Imperious Leader's body is built to resemble the reptilian race that originally built the Cylons, but is not organic in any way. According to the novelization of the pilot episode, Imperious Leaders have three distinct brains, each one capable of individual or unified thought, thereby making them adept strategists and leaders.

When an Imperious Leader is destroyed, a new one is chosen from suitable IL-series Cylons.

The Imperious Leader was never seen in close-up from the front in the series, except for a deleted scene in the pilot movie, "Saga of a Star World".[citation needed]Glen A. Larson was reportedly unhappy with the costume and requested that there be no closeup shots of it,[citation needed] although there are publicity photos that show closeups of the face. An action figure of the character was released with Mattel's Galactica toy line. Although frequently assumed to be a dummy, due to its lack of movement, there was an actor (Dick Durock) in the costume. The Imperious Leader's voice was provided by Patrick Macnee.

When Macnee appeared on camera, as the character of Count Iblis, in the two-part episode "War of the Gods," Baltar recognized Iblis's voice as that of both of the two successive Cylon Imperious Leaders with whom he had dealt. Iblis coyly countered that for his voice to be the same as either Imperious Leader's, it would have to have been transcribed into the machine leader more than 1,000 yahrens ago, and in that case, he says, "I'd have to be a thousand yahrens old!" The question is left unresolved.